Reperfusion pulmonary edema

Reperfusion pulmonary edema (RPE)

Reperfusion pulmonary edema (RPE) is a high permeability pulmonary edema which is non cardiogenic and occurs after pulmonary thromboendarterectomy. It can occur in about one tenth of patients and can range from mild postoperative hypoxemia to frank hemorrhagic pulmonary edema. The chances are higher in those with high preoperative pulmonary hypertension and in those with persistent pulmonary hypertension after surgery. Sparing of regions not reperfused at surgery has been documented, suggesting that RPE is a focal form of pulmonary edema [1].

Reperfusion pulmonary edema is also an important complication after balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension (CTEPH). It can occur in more than half of the patients after the first procedure [2]. RPE is more likely with first balloon angioplasty procedure, more so in those with higher severity of baseline pulmonary hypertension and high levels of plasma B-type natriuretic peptide. While some of them may need invasive ventilation for a few days, others can be managed with non invasive ventilation or oxygen supplementation with or without a mask. The risk of RPE comes down with subsequent balloon dilatation procedures. Pulmonary Edema Predictive Scoring Index (PEPSI) has been developed to predict the risk of reperfusion pulmonary edema [3]:

PEPSI (Pulmonary Edema Predictive Scoring Index) = (sum total change of Pulmonary Flow Grade scores) × (baseline pulmonary vascular resistance in Wood units).

Pulmonary Flow Grades were calculated similar to the TIMI (Thrombolysis in Myocardial Infarction) grading. Change in flow was the difference between pre and post procedural flow grades. Scores were calculated for each branch dilated.

Using this scoring, they showed that a lower cut off value of 35.4 had a negative predictive value of 92.3%. Aiming for a score below 35.4 and a distal pressure less than 35 mm Hg, it was possible to avoid RPE and reduce the number of balloon pulmonary angioplasty procedures. Distal pressure was measured using a pressure wire [4].

References

  1. Levinson RM, Shure D, Moser KM. Reperfusion pulmonary edema after pulmonary artery thromboendarterectomy. Am Rev Respir Dis. 1986 Dec;134(6):1241-5.
  2. Kataoka M, Inami T, Hayashida K, Shimura N, Ishiguro H, Abe T, Tamura Y, Ando M, Fukuda K, Yoshino H, Satoh T. Percutaneous transluminal pulmonary angioplasty for the treatment of chronic thromboembolic pulmonary hypertension. Circ Cardiovasc Interv. 2012; 5:756–762.
  3. Inami T, Kataoka M, Shimura N, Ishiguro H, Yanagisawa R, Taguchi H, Fukuda K, Yoshino H, Satoh T. Pulmonary edema predictive scoring index (PEPSI), a new index to predict risk of reperfusion pulmonary edema and improvement of hemodynamics in percutaneous transluminal pulmonary angioplasty. JACC Cardiovasc Interv. 2013; 6:725–736.
  4. Inami T, Kataoka M, Shimura N, Ishiguro H, Yanagisawa R, Fukuda K, Yoshino H, Satoh T. Pressure-wire-guided percutaneous transluminal pulmonary angioplasty: a breakthrough in catheter-interventional therapy for chronic thromboembolic pulmonary hypertension. JACC Cardiovasc Interv. 2014; 7:1297–1306.